English cane for a person with mobility impairment

ABSTRACT

English cane for a person with mobility impairment, comprising in its internal part a linear actuator ( 7 ) likely to transfer pulling and pushing loads and having on one hand a pair of toothed belts ( 18, 18 ′) equipped respectively with regularly spaced pads( 19, 19 ′) on their face opposed to the toothed face, and having on the other hand driving members ( 11, 11 ′) positioned on the opposed sides of said pair of toothed belts ( 18, 18 ′) and cooperating with actuating means to allow the pads ( 19, 19 ′) of said belts ( 18, 18 ′) to engage with one another, with the result that said belts are flexible and mutually independent at a first length on one side or upstream of the driving members ( 11, 11 ′), while at a second length on the opposite side or downstream of said driving members ( 11, 11 ′) said belts are securely attached and extend in a straight line as an integral rigid bar suitable to transfer pushing loads as well as pulling loads.

The present invention relates to an English walking stick for a person with mobility impairment.

A walking stick of this type conventionally comprises a telescopic tube made up of at least two tube segments which are able to slide one inside the other, namely a top tube segment and a bottom segment, incorporating an ergonomic handle at its top end, comprising a largely cylindrical part which extends transversely with respect to the longitudinal axis of the telescopic tube and which provides support for the palm, and a part which extends upwards from the part serving as a support for the palm, at an oblique with respect to the longitudinal axis of the telescopic tube and which provides antebrachial support.

There exists a large number of persons with a mobility impairment, either temporary or permanent, which is characterised by a difficulty in getting up or negotiating or getting past obstacles such as steps or gradients.

Although walking sticks, in particular English walking sticks of the known type, represent a definite aid in terms of the safety of persons using them, this aid is not always enough to render these persons totally independent if they have a relatively severe handicap and such persons have to be assisted by another person.

Accordingly, the objective of the present invention is to propose an English walking stick that is capable of giving a person with a mobility handicap greater independence in overcoming a difficulty, such as getting up from a seat, sitting down on it or tackling obstacles such as steps or gradients.

To this end, the present invention relates to an English walking stick of the type defined in the introduction, characterised in that it is equipped with a linear actuator in its inner part, capable of transmitting traction and thrust forces and comprising, on the one hand, two identical notched belts, each having regularly spaced blocks on their face opposite the notched face, and, on the other hand, driving members disposed on either side of the notched belts and co-operating with actuator means enabling the blocks of these belts to engage with one another so that the latter are flexible and independent of one another on a level with a first length disposed at one end or upstream end of the driving members, whereas on a level with a second length disposed at the opposite end or downstream end of these members, they are securely attached and extend in a straight line acting as an integral rigid bar capable of transmitting thrust forces and traction forces.

For the purpose of the invention, the driving members and the actuator means are housed in a casing secured to the top end of the top tube segment and designed to serve as an ergonomic handle, so that the first length of the 5 two notched belts extends through the part of the ergonomic handle providing antebrachial support, whereas the second length of these belts extends through the top tube segment and is secured to the internal part of the bottom tube segment by its downstream end.

When actuated, the driving members drive the sliding action of the 10 second length of the notched belts in the internal part of the telescopic tube and change the length of this tube.

The actuator means preferably comprise an electric motor with two directions of rotation, supplied with current by means of a battery of rechargeable accumulators as well as a geared speed-reducing mechanism, which is coupled with the motor and has two output pinions respectively engaging with the two notched belts and constituting the driving members.

To enable the English walking stick to fulfil its function, the linear actuator must naturally be of a power which is selected so as to be enough to impart a thrust corresponding to a substantial part of the weight of a person supporting himself on the ergonomic handle.

By virtue of another characterising feature of the invention, the linear actuator has control means borne by the ergonomic handle, as a means of controlling the on/off function as well as the direction of rotation of the electric motor.

These control means may incorporate a reversing switch with two unstable closed positions and one stable intermediate cut-off position.

A reversing switch of this type may advantageously incorporate an operating member which projects radially out from the largely cylindrical part providing support for the palm, in the region of the free end of this largely cylindrical part, so that it can be operated by a thumb of the hand of a user of the walking stick holding this largely cylindrical part.

The battery of accumulators is preferably electrically connected to an electrical connector accessible from the exterior of the casing to enable this battery of accumulators to be recharged by means of a battery charger.

In accordance with one particularly advantageous characterising feature of the invention, the casing is made up of two half-shells, in particular made from a moulded plastic material, for example polyethylene, which have a joint plane corresponding to the vertical median plane of symmetry of the ergonomic handle and are assembled by means of screws.

These two half-shells preferably each have a rib in the internal part of their part corresponding to the part of the ergonomic handle providing antebrachial support once the two half-shells have been assembled.

Together, these two ribs define a partition isolating the first flexible and independent lengths of the two notched belts.

As a result of one particularly advantageous feature of the invention, the casing has a hollow flared part in the region where the part providing support for the palm is joined to the part of the ergonomic handle providing antebrachial support, inside which the electric motor, the speed-reducing mechanism and the battery of accumulators are disposed.

Other characterising features and advantages of the present invention will become more apparent from the following description of an embodiment, given by way of example with reference to the appended drawings, of which:

FIG. 1 shows a side view, in vertical section, of a walking stick proposed by the invention;

FIG. 2 is a rear view in partial vertical section, illustrating the walking stick illustrated in FIG. 1,

FIGS. 3 and 4 are views corresponding respectively to those of FIGS. 1 and 2, showing the top part of a walking stick on a larger scale;

FIGS. 5, 6 and 7 are views in section, respectively along lines V-V,VI-VI and VII-VII indicated in FIG. 3;

FIG. 8 is a diagram showing the electric circuit used inside the walking stick proposed by the invention.

Turning to FIGS. 1 and 2, it may be seen that the walking stick proposed by the invention conventionally comprises a telescopic tube 1 provided with an ergonomic handle 2 at its top end and an anti-skid end-piece 3 made from rubber at its bottom end.

The ergonomic handle 2 comprises a part 2 a, which is largely cylindrical and extends transversely with respect to the longitudinal axis of the telescopic tube 1 providing support for the palm, and a part 2 bwhich extends upwards from the part 2 a at an oblique angle with respect to the longitudinal axis of the telescopic tube and provides antebrachial support.

The telescopic tube 1 comprises at least two tube segments, preferably three tube segments, namely a top segment 1 a, an intermediate segment 1 b and a bottom segment 1 c, which are able to slide one inside the other. The tube segments 1 a, 1 b and 1 c may be made from lightweight metal or lightweight metal alloy such as duralumin, or they may be made from a composite material with a base of carbon or glass fibres.

In a manner known per se, the walking stick may preferably have means for adjusting the length of the telescopic tube 1 to suit the size of the person or persons likely to use said walking stick. To this end, the bottom tube segment 1 c has a pair of diametrically aligned holes 4, the intermediate tube segment 1 b has two series of regularly spaced holes 5, each hole 5 of a series being diametrically aligned with the hole 5 of the other series, and a peg 6. In order to adjust the length of the telescopic tube 1, the two holes 4 of the segment 1 c merely have to be aligned with a selected pair of holes 5 of the segment 1 b and the peg 6 located in the holes 4 and 5 thus aligned.

The walking stick proposed by the invention has an actuator 7 with a reversible linear movement, which functionally co-operates with the tube segments 1 a and 1 b in order to displace them longitudinally relative to one another in the two directions.

As may best be seen from FIGS. 3 and 4, the linear actuator 7 comprises an electric motor 8 with two directions of rotation, a geared speed-reducing mechanism 9 coupled with the motor, and a thrust chain 10 which engages with output pinions 11 and 11′of the speed-reducing mechanism 9. More specifically, the speed-reducing mechanism 9 comprises a first pinion 12, which is fixed to the output shaft 13 of the motor 8 and which meshes with a gear wheel 14 integrally connected by an endless screw 15, which in turn meshes with two gear wheels 16 and 16′borne respectively by two shafts 17 and 17′to which said two output pinions 11 and 11 ′are respectively fixed so that each pinion 11 or 11′is fixed in rotation with the corresponding gear wheel 17 or 17′.

The thrust chain 10 essentially comprises two notched belts 18 and 18′, which respectively engage with the output pinions 11 and 11′of the speed-reducing mechanism 9 and which have regularly spaced blocks 19 and 19′ on their face opposite the notched face, which engage with one another in the same way as the teeth of a zip fastener. Upstream of the two output pinions 11 and 11′, in other words above these two pinions in FIGS. 3 and 4, the two belts 18 and 18′, are flexible and independent of one another, whereas downstream of the two output pinions 11 and 11′, the two belts 18 and 18′, and their blocks 19 and 19′ are joined so as to define a chain extending in a straight line and acting as a rigid bar capable of transmitting thrust forces as well as traction forces. Thrust chains such as chain 10 are well known and are described in particular in document FR-A-2 826 422, to which reference may advantageously be made for further details.

In the application where the thrust chain 10 is used in the walking stick proposed by the invention, the bottom end of the two notched belts 18 and 18′ is linked to a linking member 21, which is rigidly fixed to the top end of tube segment lb of the telescopic tube 1. The linking member 21 may be provided in the form of a block of plastic material with a generally cylindrical shape, for example, which is made by on-moulding onto the bottom end of the two notched belts 18 and 18′ so that the bottom end of the two belts 18 and 18′ is embedded and thus anchored in the block 21. The block 21 may also have a circular groove in its peripheral surface to enable it to be fixed to the top end of the tube segment 1 b, for example by crimping, as illustrated by reference number 22 in FIGS. 3 and 4.

The thrust chain 10 is dimensioned so that, in the state in which the two notched belts 18 and 18′ and their blocks 19 and 19′ are assembled, the chain 10 is able to slide inside the tube segment 1 a of the telescopic tube 1. By preference, to ensure that the chain 10 is guided correctly in the tube segment 1 a, each of the two lateral faces 23 and 24 of each of the blocks 19 and 19′ of the notched belts 18 and 18′ has a curved contour which conforms to the contour of the internal cylindrical surface of the tube segment 1 a as illustrated in FIG. 7.

The electric motor, the speed-reducing mechanism 9, at least a part of the thrust chain 10 and a battery of rechargeable accumulators 25 provided as a means of supplying the electric motor 8 with electric current are housed in a casing 26, which is attached to the top end of the tube segment 1 a of the telescopic tube 1. The casing 26 may advantageously be designed to serve as an ergonomic handle 2. The casing 26 may comprise two half-shells 26 a and 26 b made from a moulded plastic material for example, such as polyethylene for example, and have a joint plane 27 corresponding to the vertical median plane of symmetry 28 (FIG. 4) of the ergonomic handle 2. Accordingly, once the two half-shells 26 a and 26 b have been assembled and secured to one another by several screws 29, the two half-shells 26 a and 26 b together form the ergonomic handle 2 comprising its part 2 a providing support for the palm and its part 2 b providing antebrachial support.

As clearly illustrated in FIGS. 3 and 4, the casing 26 has a hollow flared part 31 in the region where the parts 2 a and 2 b of the ergonomic handle 2 are joined, inside which the electric motor 8, the speed-reducing mechanism 9 and the battery of accumulators 25 are housed. The way in which the electric motor 8, the endless screw 15, the shafts 17 and 17′ and the battery of accumulators are supported in the casing 26 is not illustrated in FIGS. 3 and 4 with a view to keeping these drawings simple and clear, but it is obvious that these elements can be supported or retained in the casing 26 by means of partitions or support elements integrally moulded with one or the other of the two half-shells 26 a and 26 b.

It may also be noted that the two half-shells 26 a and 26 b each have a rib 32 (FIG. 3) inside their part forming part 2 b of the ergonomic handle 2. Once the two half-shells 26 a and 26 b are assembled, the two ribs 32 together form a partition isolating the independent flexible parts of the notched belts 18 and 18′of the thrust chain 10 from one another upstream of the two output pinions 11 and 11′. Accordingly, this prevents any interference between said independent flexible parts of the notched belts 18 and 18′which might otherwise cause a blockage or damage to the linear actuator 7. At their bottom part, the two ribs 32 have a flared part 32 a, designed to facilitate separation of the blocks 19 and 19′ of the two notched belts 18 and 18′ when the thrust chain 10 is displaced vertically from the bottom upwards by the output pinions 11 and 11′.

A travel stop member, not illustrated in the drawings, ensures that a minimum part of the two notched belts 18, 18′ is kept upstream of the two output pinions 11, 11′ , thereby preventing any untimely dismantling of the thrust chain 10.

Underneath the flared part 31 of the casing 26, the two half-shells 26 aand 26 b, once assembled, form a cylindrical part 33 tightly surrounding the top end part of the tube segment 1 a of the telescopic tube. Although not illustrated in the drawings, other fixing screws such as screws 29, or a locking collar, may prove necessary in order to clamp the two half-shells 26 a and 26 b tightly at their cylindrical part 33 against the top end part of the tube segment 1 a. Furthermore, the top end of the tube segment 1 ais preferably shaped so that it has a lip or a collar 34 capable of engaging with upstanding elements 35 formed on the inside wall of the cylindrical part 33 of the casing 26 to prevent any relative axial displacement between the tube segment 1 a and casing 26 in one direction or the other.

Control means 36 borne by the ergonomic handle 2 are provided as a means of controlling the on/off function and the direction in which the linear actuator 7 operates. More specifically, the control means may comprise a reversing switch 37 (FIGS. 3, 5 and 8) with two unstable closed positions and one stable intermediate cut-off position. By preference, the reversing switch 37 is housed in the interior of part 2 a of the ergonomic handle 2 and has an operating member 38 which projects radially out from said part 2 a, into the region of the free end thereof, so that it can be activated by a thumb of the hand of a user of the walking stick holding said part 2 a of the ergonomic handle 2 in his hand, and can be so without the user having to release his grip of said part 2 a.

In the case of a walking stick designed to be held by the user's right hand, for example, the operating member 38 projects radially on the cylindrical surface of part 2 a of the ergonomic handle 2, in a direction directed obliquely downwards and towards the right-hand side of the user. This direction may subtend an angle of approximately 45 degrees with the vertical, for example, when the reversing switch 37 is in its stable intermediate cut-off position.

The operating member 38 is guided and is able to slide in a slot or notch 39 (FIG. 5) in the cylindrical wall of part 2 a of the ergonomic handle 2, extending in the circumferential direction. When the operating member 38 is displaced downwards in the direction of arrow F1, the reversing switch 37 tilts into one of its two unstable closed positions and controls activation of the electric motor 8 in a first direction corresponding to a downward displacement of the thrust chain 10, for example, in other words in a direction corresponding to a lengthening of the telescopic tube 1. Conversely, when the operating member 38 is displaced upwards in the direction of arrow F2, it tilts the reversing switch 37 into its other unstable closed position and controls activation of the electric motor 8 in the opposite direction of rotation, corresponding to an upward displacement of the thrust chain 10, in other words in a direction corresponding to a shortening of the telescopic tube 1 of the walking stick.

To this end, if the electric motor 8 is a continuous current motor, the reversing switch 37 may have two moving contacts 41 and 42, which are respectively connected to the positive and negative poles of the battery of accumulators 25 by conductors 43 and 44, as illustrated in FIG. 8. The reversing switch 37 also has a first pair of fixed contacts 45 and 46, which are connected respectively by conductors 47 and 48 to the two terminals of the motor 8, so that when the moving contacts 41 and 42 are in contact with the fixed contacts 45 and 46, the current supplied by the battery of accumulators 25 passes through the motor 8 in a first direction in order to rotate the motor in the first direction of rotation, causing the telescopic tube 1 of the walking stick to be lengthened. Finally, the reversing switch 37 has a second pair of fixed contacts 49 and 51, which are connected respectively by conductors 52 and 53 to the terminals of the motor 8 so that when the moving contacts 41 and 42 are in contact with the fixed contacts 49 and 51, the current supplied by the battery of accumulators 25 passes through the motor 8 in the opposite direction in order to rotate said motor in a second direction of rotation, causing the telescopic tube 1 of the walking stick to be shortened, for example.

As may be seen from FIG. 8, the two poles of the battery of accumulators 25 are also respectively connected by conductors 54 and 55 to the contacts 56 and 57 of a connector 58. As illustrated in FIG. 4, the connector 58 is fixed to the casing 26 and is accessible from the exterior of lo said casing to enable the battery of accumulators 25 to be recharged by means of a battery charger (not illustrated), fitted with a power cable terminated by a plug compatible with the connector 58.

As explained in the description above, it is clear that by acting on the operating member 38 of the reversing switch 37 in the direction or arrow F1 or in the direction of arrow F2, the user of the walking stick can cause a lengthening or shortening of said walking stick, as is the case. Accordingly, in the case of a lengthening of the walking stick, it is clear that a user supporting himself on the ergonomic handle 2 can obtain an aid to overcoming an obstacle, for example in order to climb a step or pull himself up from a seat.

The actuator 7, in particular the motor 8 and the speed-reducing mechanism 9, are preferably dimensioned so as to be capable of supplying a predetermined power, sufficient to apply a thrust corresponding to a substantial part of the weight of a person supporting himself on the ergonomic handle 2.

-   -   For example, using components having the following         characteristics:     -   electric motor 8: 17 W, 12V continuous current designed to         supply a torque of 0.058 N.m at 2800 rpm with a current of 2.5         A;     -   pinion 12: seven teeth, modulus 0.5;     -   gear wheel 14: fourteen teeth, modulus 0.5;     -   endless screw 15: a thread with an angle of inclination of 85         degrees and a friction angle of 5 degrees;     -   two gear wheels 16 and 16′ , each having fifty teeth, modulus         0.5;     -   two output pinions 11 and 11, each having a radius of 7.5 mm and         ten teeth;     -   battery of accumulators 25: 12V lithium accumulators; the         speed-reducing mechanism 9 has a reduction ratio of 1/100 and a         global mechanical yield of approximately 0.5. Under these         conditions, when the electric motor 8 is rotating at 2,800         revolutions/minute, the thrust chain 10 is displaced at a speed         of 22 mm/s and transmits a thrust force of 350N. In other words,         the walking stick is capable of lifting a weight of 35 kilos at         a speed of 22 mm/s.

In terms of electric motor 8, a motor sold under reference RE025 CLL by the MDP MOTOR company (http: / /www.mdpmotor.com) may be used, for example.

It may be noted that with the components listed above, the output of the endless screw 15 is zero when the output pinions 11 and 11′ and the gear 10 wheels 16 and 16′ are driving. This will be the case, for example, whenever the motor 8 is not supplied with current and the user of the walking stick is supported on the ergonomic handle 2. In this case, the reaction exerted by the ground on the bottom end of the telescopic tube 1 causes the thrust chain 10 to be subjected to a force directed from the bottom upwards, so that the notched belts 18 and 18′ tend to drive the pinions 11 and 11′ in rotation and hence also the gear wheels 16 and 16′ . However, since the endless screw 15 has an output of zero under these conditions, it can not rotate and it therefore blocks the gear wheels 16 and 16′ , thereby preventing any vertical movement of the thrust chain 10, either upwards or downwards. The linear 20 actuator 7 is therefore irreversible in this sense because the electric motor 8, when supplied with current, and the speed-reducing mechanism 9 are capable of displacing the thrust chain 10 in the two directions, upwards and downwards, but, conversely, the thrust chain 10 is incapable of transmitting any movement whatsoever to the speed-reducing mechanism 9 and to the electric motor 8.

The length of the thrust chain 10 is preferably chosen so that the linear actuator 7 travels a total path of approximately 30 to 35 cm.

It goes without saying that the embodiment of the invention described above was described purely by way of illustration and is not intended to be 3 o restrictive in any way and that numerous modifications may easily be made by the person skilled in the art without departing from the scope of the invention.

In particular, it is possible to provide an electronic circuit as a means of controlling the electric motor 8, for example to regulate its rotation speed. Such a control circuit can easily be mounted by means of a printed circuit board fitted in the part 2 a of the ergonomic handle 2. 

1. English walking stick for a person with a mobility impairment, comprising a telescopic tube (1) made up of at least two tube segments capable of sliding one inside the other, namely a top tube segment (1 a) and a bottom tube segment (1 b), and fitted with an ergonomic handle (2) at its top end comprising a largely cylindrical part (2 a) which extends transversely with respect to the longitudinal axis of the telescopic tube (1) and which provides support for the palm, and a part (2 b) which extends upwards from the part (2 a) at an oblique angle with respect to the longitudinal axis of the telescopic tube (1) and provides antebrachial support, characterised in that the walking stick is equipped with a linear actuator (7) in its internal part, capable of transmitting traction and thrust forces and comprising, on the one hand, two identical notched belts (18, 18′) respectively provided with regularly spaced blocks (19, 19′) on their face opposite the notched face, and, on the other hand, driving members (11, 11′) disposed on either side of the two notched belts (18, 18′) and co-operating with actuator means enabling the blocks (19, 19′) of these belts (18, 18′) to engage in one another so that they are independent of one another and flexible on a level with a first length located at one end or upstream end of the driving members (11, 11′), whereas on a level with a second length disposed at the opposite end or downstream end of these members (11, 11′), they are fixedly assembled and extend integrally in a straight line acting as a rigid bar capable of transmitting thrust forces as well as traction forces, and the driving members (11, 11′) and the actuator means are housed in a casing (26) fixed to the top end of the top tube segment (1 a) and shaped so as to serve as an ergonomic handle (2) so that the first length of the two notched belts (18, 18′) extends through part (2 b) of the ergonomic handle (2) providing antebrachial support, whereas the second length of these belts extends into the top tube segment (1 a) and is fixed to the internal part of the bottom tube segment (1 b) by its downstream end, and actuation of the driving members (11, 11′) drives the sliding action of the second length of the notched belts (18, 18′) in the internal part of the telescopic tube (1) and modifies the length of this tube.
 2. Walking stick as claimed in claim 1, characterised in that the actuating means comprise an electric motor (8) with two directions of rotation supplied with current by a battery of rechargeable accumulators (25) as well as a geared speed-reducing mechanism (9) which is coupled with the motor (8) and has two output pinions (11, 11′) which respectively move into engagement with the two notched belts (18, 18′) and constitute the driving members.
 3. Walking stick as claimed in claim 1, characterised in that the linear actuator (7) has a power selected so as to be enough to supply a thrust corresponding to a substantial part of the weight of a person supporting himself on the ergonomic handle (2).
 4. Walking stick as claimed in claim 1, characterised in that the linear actuator (7) has control means (36) borne by the ergonomic handle (2) in order to control the go/stop function and the direction of rotation of the electric motor (8).
 5. Walking stick as claimed in claim 4, characterised in that the control means (36) comprise a reversing switch (37) with two unstable closed positions and one stable intermediate cut-off position.
 6. Walking stick as claimed in claim 5, characterised in that the reversing switch (37) has an operating member (38) which projects out radially on the largely cylindrical part (2 a) providing support for the palm, in the region of the free end of this largely cylindrical part, so that it can be activated by a thumb of the hand of a user of the walking stick holding this largely cylindrical part.
 7. Walking stick as claimed in claim 1, characterised in that the battery of accumulators (25) is electrically connected to an electrical connector (58) accessible from the exterior of the casing (26) to enable this battery of accumulators to be recharged by means of a battery charger.
 8. Walking stick as claimed in claim 1, characterised in that the casing (26) is made up of two half-shells (26 a, 26 b) made from a moulded plastic material in particular, for example polyethylene, which have a joint plane (27) corresponding to the vertical median plane of symmetry (28) of the ergonomic handle (2) and are assembled by means of screws (29).
 9. Walking stick as claimed in claim 8, characterised in that the two half-shells (26 a, 26 b) each have a rib (32) in the internal part of their part corresponding to part (2 b) of the ergonomic handle (2) providing antebrachial support, and when the two half-shells (26 a, 26 b) are assembled, these two ribs (32) together define a partition isolating the first independent and flexible lengths of the two notched belts (18, 18′).
 10. Walking stick as claimed in claim 1, characterised in that the casing (26) has a hollow flared part (31) in the region where the part (2 a) providing support for the palm joins part (2 b) of the ergonomic handle (2) providing antebrachial support, inside which the electric motor (8), the speed-reducing mechanism (9) and the battery of accumulators (25) are disposed. 